1. Field of the Invention
The present invention relates to acoustic speakers and particularly to high frequency speakers which have cones with arcuated segments which extend radially which have a thickness gradient with increasing thickness radially towards its center. Thus, the present invention is directed to the pursuit of constant wave velocity generation for accurate sound reproduction at high frequencies utilizing three dimensionally defined variable thickness cones.
2. Information Disclosure Statement
The function of cones in speakers is well known and it has been accepted that a coil generates sound waves radially over a speaker cone, typically made of material capable of vibration when properly mounted. The cones were originally named as such due to the slightly "conical", configuration.
Early speaker designs are exemplified by U.S. Pat. No. 1,757,107 to Baltzley which teaches a sound generator, a tympanum having undulations extending from the central portion to the rim of the tympanum and gradually increasing in depth and width from such central portion outwardly toward the rim portion of the same and a connection for bodily vibrating said tympanum, said connection being rigidly engaged with an intermediate portion of the tympanum and supporting the tympanum for vibration in free air responsive to the movements of said connection.
U.S. Pat. No. 1,787,946 to LaRue wherein a suspended diaphragm is used. However, conventional acoustic speakers involved diaphragms of the aforesaid basic conical design wherein it radiated outwardly about a coil. Subsequent improvements led to the acoustic diaphragm having a honeycomb cone, e.g. of a plurality of laminated metal foils, the adjacent metal foils being adhered at a regular pitch.
U.S. Pat. No. 4,013,846 to Krawczak describes an electroacoustic loudspeaker having a rigid, lightweight diaphragm and a substantially closed loop magnet support of a magnetically permeable material having a channel-shaped cross-section and supported adjacent and spaced from the diaphragm with the open side of the channel facing the diaphragm. The magnet support carries a pair of magnets magnetized and positioned with opposite poles in spaced facing relation and a voice coil is secured to the diaphragm and lies in the gap between the magnets.
U.S. Pat. No. 4,300,655 to Sakamoto et al describes an acoustical diaphragm which is made of a cone member of elongated web material bent to have a plurality of radial projections sandwiched between upper and lower flat components. It is indicated by the invention therein that increased speaker power is achieved due to model line reshaping. While this patent is concerned with radial sound wave generation it is not directed to the type of system represented by the present invention wherein constant wave velocities are sought at high frequencies utilizing arcuated speaker segments which tend towards flattening as the radial distance increases.
U.S. Pat. No. 4,655,316 to Murray describes an acoustic diaphragm which is made of metallic sheet material forming a raised pattern of the material and unraised sectors of the material. The diaphragm is of the dome-shaped variety. The raised pattern incorporates sets of raised strip elements. There is a set of such elements extending radially from the vicinity of the apex. There is a set extending along areas of the sheet material between the radially extending elements, this second set including pairs of strip elements, this second set including pairs of strip elements which intersect one another along such areas. There is also a set of circumferentially extending raised strip elements. The form of the radially extending elements changes along their lengths; for example, they rise to levels which vary along their lengths.
U.S. Pat. No. 4,811,403 illustrates various types of horns for ultralight loudspeakers. This patent describes a loudspeaker and enclosure assembly which includes a load bearing member exhibiting good thermal conductivity; at least one loudspeaker mounted on the load bearing member and in thermal engagement therewith; and its enclosure having walls formed of rigid lightweight material mounted on the load bearing member to enclose the at least one loudspeaker, whereby the assembly is easily moved and mounted and thermal energy generated by operation of the loudspeaker is effectively dissipated through the load bearing member. The enclosure may be a rigid foam-filled member defining a generally funnel-shaped bore therein to form a horn for the loudspeaker, whereby a modular construction of interchangeable integrally formed enclosures and horns can be achieved. However, this patent does not show the type of arrangement or assembly specifically claimed herein.
U.S. Pat. No. 4,862,508 to Lemon describes an improved method for transmitting sound at high power levels over a wide angle zone of dispersion without distortion, comprising the step of emitted sound waves from a plurality of individual sources, each characterized by a relatively narrow, wedge-shaped envelope of sound projection, such that adjacent edges of respective sound projection envelopes are in substantial alignment and do not overlap, whereby the absence of interferences between sounds emitted from different sources precludes sound distortion and enables uniform sound dispersion and high sound quality throughout the zone. The sound waves are preferably emitted from electroacoustical loudspeakers having loudspeaker enclosures shaped to conform to the edges of their respective sound envelopes.
U.S. Pat. No. 4,881,617 to Alexander Faraone describes an acoustic speaker having a cone located about a transducer wherein the cone has a plurality a thin, pie-shaped segments radiating outwardly from the transducer with each of the segments having an arcuated cross-section, thereby creating a concave side and a convex side.
The above-described patent to Alexander Faraone, the inventer herein, is directed to cones having configurations which are concave towards the center whereas the present invention high frequency center cone has other unique and unobvious characteristics, including being convex towards it center, being unistructurally formed and being located about a voice coil support tube in a different manner.
Notwithstanding the prior art, the present invention is neither taught nor rendered obvious thereby.